This invention relates to a device for adjusting the length of a strip of material such as a belt, a band, a shoulder strap or the like to be worn or used on trousers, skirts, undergarments or the like.
Various types of such devices have been proposed. One of the most commonly used types comprises a combination of two component members. One of the component members comprises a rectangular metal plate having its opposite lateral portions bent in such a manner that a central cover portion and a pair of opposite side portions perpendicular thereto are formed, with a bearing hole formed in each of the side portions, while the other component member comprises a rectangular metal plate having an end portion bent substantially perpendicularly to the remaining main portion of the plate, with a pair of pivot pins projecting laterally from the opposite lateral edges of the bent portion so as to be received in the bearing hole of the first component member.
The disadvantages of this type of buckle are that since the two component members are made of rigid material which lacks resiliency, repeated movement of the second relative to the first component member causes deformation of the bearings thereby to reduce the force to fasten and hold the band, and that the outer ends of the pivot pins laterally projecting from the opposite sides of the buckle not only make its appearance bad but also are likely to damage the clothes of the wearer.
In an effort to overcome the above-mentioned disadvantages of the known type of buckle, the present inventor has studied various designs of buckles while conducting many experiments and found out that by changing the positional relation between the pivot pins and the bearing it is possible to avoid the above-mentioned defects of the conventional device.